Tamsulosin hydrochloride

Description

Tamsulosin is a potent antagonist of α₁-adrenergic receptors (α₁-ARs; K_i = 0.229 nM in a radioligand binding assay). It is 3,800-fold selective for α₁-ARs over α₂-ARs (K_i = 871 nM). Tamsulosin antagonizes norepinephrine-induced contraction of isolated rabbit aorta (pA₂ = 10.11) but has no effect on contraction stimulated by histamine, serotonin , angiotensin II , or prostaglandin F_2α . In vivo, tamsulosin reverses the pressor effect of phenylephrine (Item Nos. 17205 | 18619) in pithed rats. It reversibly reduces fertility in male rats when administered at a dose of 0.15 mg/kg. Tamsulosin (1-100 μg/kg) also reduces prostatic pressure in a dose-dependent manner with minimal hypotensive effects in anesthetized dogs. Formulations containing tamsulosin have been used for the treatment of benign prostatic hyperplasia.

Chemical properties

White to Off-White Solid

Originator

Contiflo OD,Ranbaxy Laboratories,India

The Uses of Tamsulosin hydrochloride

Specific a1-adrenoceptor antagonist. Used in the treatment of benign prostatic hypertrophy

The Uses of Tamsulosin hydrochloride

Specific α1-adrenoceptor antagonist. Used in the treatment of benign prostatic hypertrophy.

The Uses of Tamsulosin hydrochloride

antineoplastic, alkylating agent

The Uses of Tamsulosin hydrochloride

(R)-Tamsulosin is a specific α1-adrenoceptor antagonist. It is used in the treatment of benign prostatic hypertrophy.

The Uses of Tamsulosin hydrochloride

An α1-adrenoceptor antagonist

Definition

ChEBI: Tamsulosin hydrochloride is a hydrochloride resulting from the reaction of equimolar amounts of tamulosin and hydrogen chloride. It has a role as an alpha-adrenergic antagonist and an antineoplastic agent. It contains a tamsulosin(1+). It is an enantiomer of an ent-tamsulosin hydrochloride.

Manufacturing Process

In 1,000 ml of acetonitrile was suspended 17 g of 5-{2-[2-(2- ethoxyphenoxy)ethylamino]-1-hydroxy-2-methylethyl}-2- methoxybenzenesulfonamide hydrochloride and while stirring the suspension, 9 g of thionyl chloride was added dropwise to the suspension at room temperature, whereby the product first dissolved and then began to crystallize gradually. After stirring the mixture for two days, the crystals formed were recovered by filtration, washed with chloroform and dried to provide 15 g of 5-{1-chloro-2-[2-(2-ethoxyphenoxy)ethylamino]-2-methylethyl}-2- methoxybenzenesulfonamide hydrochloride. Melting point: 197°-200°C.
In methanol was dissolved the 5-{1-chloro-2-[2-(2- ethoxyphenoxy)ethylamino]ethyl}-2-methoxybenzenesulfonamide hydrochloride and after adding thereto 10% palladium carbon, dechlorination was performed under hydrogen stream at normal temperature and pressure. The palladium carbon was filtered away and the filtrate was concentrated under reduced pressure to provide the 2-methoxy-5-{2-[2-(2- ethoxyphenoxy)ethylamino]ethyl}benzenesulfonamide hydrochloride, which was recrystallized from 120 ml of a mixture of methanol and ethanol (1:4 by volume ratio) to provide the colorless crystals thereof. The melting point of the 5-{2-[2-(2-ethoxyphenoxy)ethylamino]-2-methylethyl}-2- methoxybenzenesulfonamide hydrochloride: 254°-256°C.

Therapeutic Function

Antihypertensive

Mechanism of action

Tamsulosin hydrochloride is an alpha blocker. It works to relax the smooth muscles in your prostate and bladder. This makes it easier to pee and improves the flow of urine.

Side Effects

Common side effects include dizziness, headache, sleeplessness, nausea, blurry vision, and sexual problems. Other side effects may include feeling lightheaded with standing due to changes in blood pressure, and angioedema.

General Description

Tamsulosin hydrochloride is a subtypeselective a₁A and a₁D adrenoceptor antagonist, which exists in two enantiomeric forms, of which the R-isomer is the pharmaceutically active component. It is used to reduce urinary obstruction and is also involved in relieving the symptoms associated with symptomatic benign prostatic hyperplasia.

Hazard

Moderately toxic by ingestion.

Biological Activity

Selective α 1A -adrenoceptor antagonist (pK i values are 9.97, 9.64 and 8.86 for α 1A , α 1B and α 1D subtypes respectively). Decreases resting maximal urethral pressure with negligable effect on mean arterial blood pressure in vivo .

Biochem/physiol Actions

Tamsulosin is an α1A/1D-adrenoceptor antagonist used as a treatment of benign prostatic hypertrophy (BPH). Its activity as an ? blocker also affects the iris, and has led to complications during cataract surgery, a condition called "floppy iris" syndrome.

Storage

Desiccate at RT